Ramblings about projects I work on during my "copious free time" (CFT).

Thursday, February 24, 2011

Rc - Making shell scripting suck less

There are some tremendous ideas behind the ubiquitous Unix shell (um, that would be Bourne, bash, (d)ash or maybe ksh?). The problem is that a lot of these ideas are very, very dated. Bash is probably the best example of how to keep a Unix bourne dialect alive. Ksh was beastly (tons of features), but I think bash has finally passed it. But is this a good thing?

As I start writing more complex scripts I begin to feel the age of Bourne. I have been using (d)ash (due to it being the Busybox shell and much smaller than bash -- GNU seem to be set on add the kitchen sink to every tool.) You can pretty much do general purpose scripting with Bash, but still with the legacy syntax of Bourne. You might as well go with Perl or Python (and their associated huge installation footprints).

Then there is rc (the Plan 9 shell). It starts with Bourne and "fixes" things rather than tack on stuff around the edges. It is very minimalistic and has a certain elegance I haven't seen since Awk. Plan 9's toolbox minimalism was an attempt to get back to the origins of Unix (lots of small single purpose tools). The famous anti-example of this is probably GNU ls. Look at the options, the many, many options.

Rc isn't actively supported much (Plan 9 has since faded -- if it ever shone brightly to begin with), but it has the feel of something well thought out.

You'll hear more from me about that in upcoming posts.
Time to shut up and code.